1. Field of the Invention
The present invention relates to an imaging apparatus which calculates a histogram.
2. Description of the Related Art
Recently, many digital cameras can generate a histogram in which image data is counted in terms of luminance. For example, Japanese Patent Application Laid-Open No. 2002-84440 discusses a digital camera which can reduce the time necessary for histogram processing. In such a digital camera, the image data size is resized and reduced, and the histogram is calculated based on the reduced image data. As a result, the time necessary for histogram processing is shortened.
Further, Japanese Patent Application Laid-Open No. 2003-244487 discusses a digital camera which can reduce a load on a system by efficiently performing histogram processing. Such a digital camera is controlled to calculate the histogram when a shooting condition changes, so that a processing load is reduced.
The digital camera calculates the histogram from image data of a still image and optimizes signal processing settings according to the resulting histogram to improve image quality. However, time required for calculating the histogram from the image data of the still image is simply added to time required for developing the still image, so that performance is lowered.
On the other hand, since the digital camera calculates the histogram to acquire a setting value for performing developing processing, image data before developing processing is employed as an input image for histogram processing. However, color balance is not corrected in the image data before developing processing, so that the resulting histogram does not correctly reflect the shooting condition.